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Comment by sdevlin | Hacker News Reader

Report coauthor here.

No significant issues were found in either phase of the TrueCrypt audit. If you're using it today (or have used it in the past), I don't think you have anything to worry about.

But it is an unmaintained piece of software, and for that reason I would migrate away from it. If I were setting up a new laptop today, I wouldn't consider installing it. If I had an existing laptop using it, I would think about transitioning when I had some spare time.

Not a hair-on-fire problem, though.

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All else being equal it would make sense to move. But all else isn't equal and having an audit and knowing the programmer knew their stuff enough to pass the audit (especially since this is in the crypto field) seems to be a huge benefit that other projects can't match right now.

BitLocker and Filevault were almost certainly reviewed more carefully than Truecrypt was (I didn't participate in either audit, but can confirm that both of those companies allocate significant resources to third-party audits).

Yeah, better trust US companies who are subject to NSA, which has been proven to require no backdoors in software /s

If those companies wanted to subvert your TrueCrypt installation, they would have an easy time of it.

Could you sketch how, so we can think about countermeasures?

MITM the http connection you used to download truecrypt?

I assume MITM your https connection by manipulating CAs.

Or use one of their 0days to breaking into your machine and get your data while it is decrypted in memory or just steal your password.

I would assume both Windows and Mac are compromised to the level of C&C by the NSA. In a threat model that includes them I would not use either. But I would still think Windows + TrueCrypt is better than Windows + BitLocker.

Do you mean "NSA has stockpiled vulnerabilities they've discovered in Win8 that would enable them to quickly enroll a networked Win8 box into a C&C"? If so: sure, I agree.

Do you mean "NSA has implanted backdoors into Win8 that would enable them to directly enroll a Win8 box into a C&C"? If so: virtually nobody who does professional vulnerability research, myself included, agrees.

The distinction matters here, because if all you're saying is the former thing, that impacts Truecrypt just as much as Bitlocker, because it's equally true of every operating system, including Linux, FreeBSD and OpenBSD.

Does it have an implanted back door? I don't know. Can it give one to Microsoft and say push it out as an update for these individuals and if you say anything you'll end up in prison? That is the problem with secret courts.

This seems silly, but Microsoft appears, on the surface, to have purchased Skype with the intention of selling surveillance to the NSA. They immediately replaced the whole network architecture and encryption setup with something that had weaker security and was subject to compromise of Microsoft.

That's the sort of player we're dealing with, and that's why Bitlocker is not just improvably secure, it is best to simply assume that there are deliberate backdoors, whether any particular employee knows of them or not.

Skype's peer-to-peer networking was entirely unsuitable for running on mobile devices, the new default market. I was never able to leave it logged in on my phone before, or else I'd only have half the usual battery life.

And that's a justification for changing the way non-mobile devices handled skype?

Easy, but not as easy. I'm not saying that something is 100% secure, I'm saying that option A is better than option B.

Of course. I mean once your threat model includes secret shadowy intelligencia overlords that can bend corporations to their will, there's just no way they could tamper an audit.

They could even force the CPU makers to include backdoors directly in the silicon ;)

truecrypt had a software AES implementation you could enable.. if seriously paranoid.

performance impacting though.

That one layer of security may be compromised with no possible recourse does not mean that one should abandon considerations of compromisation of other layers that do have recourse.

See: Trusted Platform Module (TPM)

Between China and the USA, there's almost certainly hardware backdoors in place for some systems. IIRC there has been evidence of router tampering for ISP hardware shipping across borders.

Certainly reviewed more and certainly infected by the NSA more. Until the taint of the NSA has been removed those are outright no gos.

I feel like a lot of people probably think the way you do: that software for which source code isn't available is trivially backdoored by NSA. In fact, huge chunks of the billion-dollar software security industry are premised on the idea that this isn't true at all: that you can, for instance, recover the control flow graph from a binary compiled program, and then from that recover an intelligible IR, and then examine that for security flaws.

Where, exactly, do you suggest that NSA could have tainted Bitlocker in a manner that wouldn't also implicate Truecrypt?

It goes like this:

NSA: "Hi, can you please let us see your source code."

(The conversation below happens in your head): <thought-bubble>

"Do I want to spend the next 15 years and all my money and life trying to stay out of jail?"

"Do I want the IRS to know about trips to the Cayman Islands?"

"Do I want my wife to know about my mistress?"

</thought-bubble>

Me/You: "Sure no problem!"

I know its nice to think about that we would the moral high ground.

Try doing it alone with just a nice government official.

This is in no way responsive to my comment, which wasn't about whether the USG would coerce Microsoft.

Possibly contrived example: An airgapped Windows machine. We've eliminated the possibility of any data exfiltration (all the software vulnerabilities in the world can't transmit on a downed interface), but that does not mean that the encryption itself is not defeated in some way by the existence of a "master key" or some other flaw that allows an attacker to access the data offline.

Truecrypt has now been proven to have no such flaws.

It's unlikely that Bitlocker will ever be proven in the same way.

Anyone that has a legitimate fear of that kind of attack, the bad guys with guns coming in and seizing your stuff, would use Truecrypt over Bitlocker out of an abundance of caution.

Why exactly is it hard for reverse engineers to discover how Bitlocker is keyed? If it's because it colludes with compromised hardware, why isn't that just as problematic for Truecrypt?

It isn't necessarily - but there's a lot of places to hide in a large set of binary blobs. Can any effort spent reverse engineering any program (let alone an operating system!) compete with a line-by-line audit of the source of a single program?

Compromised hardware is another matter entirely. The old rule is, "if an attacker has physical access to your machine, it's not your machine anymore", and it's no less true here.

It's funny you should mention it, because the Windows kernel is among the more comprehensively reverse-engineered codebases in the industry.

I would just use the built-in disk encryption solutions your platform offers. This is also what the TrueCrypt developer recommends.

> This is also what the TrueCrypt developer recommends.

You can't be seriously deferring to that? The end-of-the-line announcement was so completely out of sync with all previous communications from the TC devs, so un-TrueCrypt like, that everything it said should be taken with a huge grain of salt. _Especially_ any advice pertaining to better managing one's security needs.

I'm not sure I know of a professional cryptography engineer who believes that what happened with Truecrypt is anything more than what that developer said. Can you cite one?

They believe that, huh? Interesting wording.

What convinces me that there is more to the story is what they haven't said.

But maybe what they did today makes that impossible. They set the whole thing on fire, and now maybe nobody is going to trust it because they’ll think there’s some big evil vulnerability in the code. But now this decision makes me feel like they’re kind of unreliable. Also, I’m a little worried that the fact that we were doing an audit of the crypto might have made them decide to call it quits. - Matthew Green

TrueCrypt's developers chose not to graciously turn their beloved creation over to a wider Internet development community, but rather, ... to attempt to kill it off by creating a dramatically neutered 7.2 version ... - Steve Gibson

I have no idea what's going on with TrueCrypt, Speculations include a massive hack of the TrueCrypt developers, some Lavabit-like forced shutdown, and an internal power struggle within TrueCrypt. I suppose we'll have to wait and see what develops. - Bruce Schneier.

Matthew Green does not believe there is a Truecrypt conspiracy. Source: I've discussed this with him at length as an advisor to the TC audit project.

Steve Gibson isn't a cryptographer, and your quote doesn't respond to my question.

Bruce Schneier I'll have to accept as a totally valid rebuttal to my implied point. This is something that really irritates me about Schneier, for what it's worth. He's also behind a meme that elliptic curve cryptography is less safe than RSA, when the reality is almost the opposite.

I think those quotes were a bit snotty, especially considering your stature and knowledge on this. I don't think I was trying to rebut you, as much as I was simply trying my luck at advocating that user's view. Sorry for that.

I wouldn't say I'm "deferring" to it. It does align with what I think is the best option.

> This is also what the TrueCrypt developer recommends.

Given the context of the thread, how is this not using developer's recommendation as an endorsement? What TC dev said bears absolutely zero weight regardless of whether it aligns with your opinion or not.

The context of the thread is a report with my name on it.

My professional opinion is my own. The developer's opinion is also relevant (to people who don't buy into nonsensical conspiracy theories), so I mentioned it.

What's your opinion of XTS in general for disk encryption?

Are there any known exploitations of weakness in XTS that might work their way back to TrueCrypt?

Most folks use TrueCrypt's disk encryption as a "file container", when they effectively want to encrypt files. Do you know of any tools (cross-platform or otherwise) that would provide the same UX as TrueCrypt while not relying on FDE?

I think it's fine. For the limited threat model FDE is equipped to handle, XTS does the job.

I'm not sure what the best answer is to your second question. I wouldn't use TC for that. I would typically use PGP, but I don't think it has a good UX for general consumption. There may be room for someone to build a better product.

Coincidentally (?), You Don't Want XTS (2014) https://news.ycombinator.com/item?id=9312599 was re-posted today, opining on this question.

As far as I can gather the Dutch authorities are not able to retrieve TrueCrypt keys. I can not say the same about BitLocker and FileVault. If the US knows how to get into TrueCrypt volumes then at least they are not sharing that knowledge with foreign allied agencies.

Any input on the cryptic message the TrueCrypt developer left on their website, essentially saying we should all assume TrueCrypt to be insecure?

I don't have any inside knowledge, but I don't think there's any cloak-and-dagger stuff here. I think he just didn't want to maintain it anymore (for whatever reason), and he wanted to warn people away from using unmaintained software.

Again, this is just my perception.

The developers themselves have clarified. Software that is not actively maintained should be assumed to be insecure.

link/source?

The Security Now show from the week after the event had a pretty thorough recounting of what happened. I'd recommend starting there.

Security Now! episode #458 - 10 Jun 2014

Skip to 2 minutes in if you don't want to hear the drawn out intro

https://media.grc.com/sn/sn-459.mp3

https://www.grc.com/sn/sn-459.htm

out of curiosity then, what would you use? I've been trying to figure out an alternative.

I'm primarily a Mac user, and I use FileVault. If I were on Windows, I would use BitLocker. I'm not sure about Linux.

For Linux, dm-crypt/LUKS for full-disk encryption (this is already the default on many distros) and eCryptfs for less complete or individual file/directory encryption.

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